Typewriter key touch controlling means



N 1953 c. H. KENNEDY, JR 2,660,285

TYPEWRITER KEY TOUCH CONTROLLING MEANS Filed April 24. 1951 2SheetsSheet l INVENTOR. CHARLES H- KENNEDY JR.

ATTORNEY Nov. 24, 1953 C. H. KENNEDY, JR

TYPEWRITER KEY TOUCH CONTROLLING M* CANS 2 Sheets-Sheet 2 Filed April24, 1951 FIG-3 FIG FIG-6 FIG *5 INVENTOR CHHRLES H. KENNEDY JR.

ATTO R N EY Patented ov. 24, 1953 Toc'on CONTROLLING TYPEWRITER KEYMEANS Charles H. Kennedy, Jr., North- Syracuse, N. Y., assignor to L. C.Smith & Corona Typewriters; Inc Syracuse, N. Y., a corporation of NewYork Application April 24, 1951, Serial No. 222,643

9 Claims. (01. 197-33) writer key touch controlling means and isadapted. for use especially to efiect variable regulation of theoperating touch of the set of printing keys of a typewriter.

One object of the invention is to provide simple, efiicient andeconomical means adapted for 00- action with a key, or a set of keys, ofa typewriter to regulate the operating key touch and which readily maybe set variably by a typist to. change the operating key touch.

Another object of the invention is to provide improved touch controllingmeans for the spring returned keys of a typewriter whereby the effectiveforce of all of the key return springs of the typewriter readily may beregulated collectively by an assembly or repair man and the typistreadily may increase selectively the heaviness of the touch of theprinting keys of the typewriter without affecting the regulation of theefforce to completion of key operated movements of the universal bar inall effective set positions of the device but becomes initiallyeffective at a point in such bar movements which diiiers in accordancewith the difierent effective settings of the device; and which does notmove, in whole or in part, in response to movements of the universal barwhile the device is in its inefiective Set position.

A further object of the invention is to provide a key touch controllingcoil spring and improved variably settable supporting means anchoringsaid spring at its ends and operable in response to operating keystrokes to stretch said spring an extent which varies in accordance withdiifer ent settings of said means.

To the above and other ends, which will hereinafter appear, theinvention consists in the features of construction, arrangements ofparts and combinations of devices set forth in the following descriptionand particularly pointed out in the appended claims.

In the accompanying drawings:

Fig. 1 is a fragmentary top plan View of a key operated front striketypewriter equipped with touch controlling. means embodying theinvention 2 in its preferred form, many parts of the typewriter beingomitted and others broken away for better illustration of the invention;

Fig. 2 is a fragmentary vertical longitudinal sectional view of themachine on the line 2-2 of Fig. 1 with certain parts omitted and othersbroken away;

Fig. 3 is a detail sectional view on the line 3 3 of Fig- 1;

Fig. 4 is a fragmentary right hand side elevational View of the machine;

Fig. 5 is a detail sectional view on the line 5- 5 of Fig. 1 showing thesettable touch control device set .for lightest touch; and

Fig. 6 is a view similar to Fig. 5 showing the settable device set forheaviest touch.

Only so much of the typewriter is shown and will be described as isnecessary to a full understanding of the present invention.

The stationary main framework of the type;- writer comprises rigidlyconnected parts, including two side plates It and H, three horizontalcross bars l2, I3 and I4, a key lever guide it, and a horizontal keylever return stop device It. Each type bar of the machine, one of whichis shown in part at IT, is actuative to printing po-- sition' by aseparate printing key, certain of these keys being shown and designated58'. The printing keys are carried by individual key levers, some ofwhich are shown and designated iii. The key levers support the printingkeys in four banks and all are fulcrumed at their rear ends on ahorizontal pivot rod 20 and carried by cross bar l2.

Each key lever is provided with a laterally ex tending pin 2 I engagedin a slot 2-2 in one arm of a diiferentone of a set of belloranksub-levers 23 all of which are fulcrumed on a'horizontal pivot rod 24carried by crossbar i l. The pins of the key'levers of each bank'arestaggered relativelyto those of each of the other banks, as indicated inFig. l, for uniform rocking of all of the bellcranks. Each bellcrank isdrivable by its conneoted key lever, on the operating strokes of theprinting key on said lever, to actuate an associated one or the typebars to printing position through a suitable individual bellcrankandtype bar connecting linkage, one such linkage being shown in part at 25(Fig. 2).

The several type bar actions are restored to normal position byindividual return springs 26 which are anchored at their ends to thebellcranks and a return spring anchor bar 21 to normally yieldingly holdthe type bars retracted from printing position and hold the key leversrocked against the key lever stop device. The anchor bar comprises twowelded or otherwise rigidly connected metal strips.

The typewriter has a key operated universal bar 28 fixed on a horizontalrock shaft 29 journaled at one end on a pivot screw 30 carried by sideplate [0, said shaft having a reduced end portion journaled at 3! in asheet metal bracket 32, which is fixed to side plate I. The universalbar is employed to actuate certain mechanism of the typewriter includinga part 33 pivoted at 3% to a pendent arm of a lever 35. Lever 35 isfixed to the rock shaft and has an upwardly extending stop arm carryinga suitable bumper 36 which normally abuts an upstanding stop arm 32aformed on bracket 32, which arm 32a is bendably adjustable fore and aftof the machine to adjust the normal or returned position of theuniversal bar. In its normal returned position, the universal barextends across the machine with its lower portion spaced slightlyforward of the upwardly extending arms of the bellcranks 23, said barbeing rockable forwardly by any actuated one of the bellcranks on theoperating or down strokes of the key actuating that bellcrank and aftera slight initial depression of said key. A spring 31 (Fig. 4) isconnected to part 33 and the lower end of lever 35 to return theuniversal bar.

It is desirable that the key touch of a typewriter readily may beregulated by individual typists, but it is undesirable that, by suchregulation, the effectiveness of the key returning springs may be soreduced as to adversely affect proper functioning of the machine. of theeffective force of the key lever return springs should be confined torepair men and typewriter production men, and variation by typists ofthe normal key touch thus established should be efiected by means otherthan variation of the normal tension of the key lever return springs.Furthermore, a typewriter commonly has at least 42 key lever or otherreturn springs for the type actions, one for each type action, and itrequires considerable effort to collectively adjust their tension.

The means shown whereby the normal touch may be established bycollective adjustment of the normal tension of the type action returnsprings, and whereby such normal touch readily may be varied by thetypist, without altering the effective force of the return springs, nowwill be described.

The provision for collective adjustment of the normal tension of thetype bar action return springs 26 comprises supporting the spring anchorbar 2? on a plurality of adjusting screws 38 which extend looselythrough holes in, and spaced along, bar 13 with said screws threadedthrough the spring anchor bar 2? and abutted against the rear edge ofbar it. By turning the screws 38 with a screw driver the spring anchorbar may be shifted along the screws substantially longitudinally of thereturn springs 2t. Preferably, at suitable intervals along bars l3 andI4, screws 39 pass loosely through rigid metal spacing sleeves 40 whichextend through clearance holes in anchor bar 2? with the ends of thesleeves abutting the bars #3 and Hi to maintain a fixed spacing betweensaid bars throughout their lengths.

The invention is concerned primarily with the further provision oftypist settable means whereby the desired normal minimum key touchestablished by adjustment, as above described, of

Regulation the type action return spring anchor bar, may be variedwithout changing the effective force of the return springs, and thistypist settable means new will be described.

An upstanding tappet arm Al is fixed on the left hand end of the rockshaft 29 adjacent the inner face of side plate It! to rock with theuniversal bar 23. Full depression of any key it, i. e. depression ofsuch key until arrested by engagement of a type on the connected typebar with paper backed by the platen (not shown) of the typewriter,drives the connected bellcrank 23 and the universal bar 28 and tappetarm H from their respective normal positions, shown in full lines inFigs. 5 and 6, to those shown in dotted lines in said views.

A readily hand settable spring device is mounted on side plate Ill andis located at the inner side of said plate for coaction with the tappetarm 4! to regulate variably the touch of all of the printing keys 18 ofthe typewriter. While, if de sired, the range of setting movements ofthis device obviously may be such that it will influence the key touchin all set positions of the device, its setting range preferably, and asshown, is such that said device is so positioned at one limit of itssetting range as to have no influence on the key touch, as will appearfrom Fig. 5 and be explained more fully.

The spring device comprises two sheet metal bellcrank levers a2 and 43and an auxiliary touch regulating spring 44. Each bellcrank lever has anupstanding arm and an arm extending rearward from the lower end portionof said upstanding arm. The two levers are pivoted side by side on apivot screw 45 at the lower ends of their upstanding arms and areconfined, adjacent said screw, between the head of the screw and theinner face of side plate [0, said screw being threaded into said plate.The upstanding arm of lever s2 is formed with a finger piece :32?) ablein and along a closed slot 46 in a sheet metal bracket M, which bracketis held to the side plate 10, at the inner face of said plate, byclamping screws 48 threaded into said plate. To permit adjustment of thebracket 4! fore and aft of the typewriter, the shanks of screws 38 passthrough elongated slots 49 in said bracket. The upstanding arm ofbellcrank lever 32 is inherently laterally resilient to releasably holdthe lever in different set positions through selective engagement offinger piece 32b in different ones of a series of notches 59 formed inbracket 4? along one edge of slot 46. Suitable index numerals may beprovided on the bracket opposite notches 5&3, such as the numerals 1 to5 shown on said bracket in Fig. 1.

The before-mentioned rearwardly extending arm of lever $2 is formed witha stop lug 22a for engagement with the rearwardly extending arm 43a oflever 33. The lever 42 has a second rearwardly extending arm 620 higherup thereon, and a coil spring M has one of its end coils hooked to arm520 at 55. The other end of spring Gd has a coil hooked to the arm 63aof lever 3 at 52. The rearwardly extending arm 30: or" the lever 43 isthus normally held engaged with the lower edge of stop lug 52a by apredetermined normal pull exerted on levers 42 and as by the spring 44.

Lever 43 is formed at the upper end of its up standing arm with a tappetlug 43b in the path of rearward movement of the upper end of tappet arm45. Lever 53 thus is an anchor for one end of spring 46 and is drivableby the universal bar to progressively stress said spring, while lever 42is an anchor for the other end of said spring and is settable to holdthat end of the spring 1 tionary in different positions.

It will be obvious that the setting range of the. spring device d2lt-lid is limited. by the length of the slot 46 in bracket d! and issuch that the setting of the device maybe changed without any change ofthe normal relation of parts 42943-1441 or of the normal tension ofspring 54. The set.- ting of the device may be changed merely byshifting the finger piece d2?) from any notch 50 to another of saidnotches. It further will be obvious that driving of the lever at bytappet arm ii will progressively stretch spring 44.

In Figs. 1 to 5 the typewr'iteris illustrated with the spring device setin its ineifective position in which finger piece 42b of lever 82 isengaged in the rearmost notch 50 in bracket 41. In this setting of thedevice, the tappet lug 43b on lever 43 is spaced a substantial distancebehind tappet arm dl so that, on the operating down stroke of any keyit, said tappet arm will not rock lever 43 to stretch spring 54, saidspacing preferably being such that the tappet arm and lug, as shown indotted lines in Fig. 5, do not come into contact when the keys areoperated.

In Fig. 6 the spring device is shown set for the heaviest touchprocurable within its range of setting adjustment, the finger piece 421)in this setting of the device being engaged in the foremost notch 50 inbracket 41. In this setting, the tappet arm and tappet lug are (as shownin Fig. 6) normally substantially in contact and, on the down oroperating stroke of any printing key [8, the lever d3 will be rocked. atleast substantially throughout the key operated movement of theuniversal bar and. will progressively stretch the spring d l until theoperating stroke of the key is completed. In the several intermediatesettings afforded by the remaining notches 5G in bracket M, thestretching of spring 44 will be started at different later points in thekey driven movements of the universal bar, thereby varying the extent ofstretching of the spring 44 to vary the key touch.

It will be observed that the initial resistance of the spring at to keydepression always remains the same, but that the spring resistancestarts, in each different effective set position of the spring device,at a different point in the down stroke of any key and thereafterprogressively increases until such stroke is completed. This feature,and that of the'normal spacing between the universal bar and bellcranks23, permits easy starting of the type bar actions without undesirablefinger shock in all settings of the spring device. It affords also acushioning of the typists fingers which increases in effectiveness asthe device is set for heavier and heavier touches.

It further will be noted that the setting lever 52 and the springstressing lever d3 of the spring device d2d3d4 support the coil spring44; that this spring is securely anchored at opposite ends thereof todifferent ones of these levers; that spring ts normally yieldinglymaintains the spring device conditioned for variable setting movement asa unit about the supporting pivot 35; and that the spring device isoperable by the universal. bar to stretch the spring 44 but is supportedentirely independently of the universal bar.

Further, the spring device can be rendered ineffective at will and,being free of attachment to the universal bar, no part of the devicewill move when the device is set in ineffective position.

I laim:

1. A variable ey touch pe r t r ha in in combination, a universal bar,key actions indii ua perab t mpart fi r p w r st e to the bar, a returnspring connected with the bar to stro-kethe bar to a rest position, anauxiliary spring for regulatin the operating touch of the key actions,an anchor for the auxiliary spring drivable by finger powered strokes ofthe bar thercagainst and returnable by said auxiliary spring, and aholding anchor for the auxiliary spring adjustable to arrest saiduniversal bar drivable anchor in different selected returned positicnsin all of which said auxiliary spring is maintained under the samestress by its said justable about a fixed axis, and wherein saiduniversal bar drivable anchor is rockable about said axis relativel tothe holding anchor and is constrained by said spring into arrestedengagement with the holding anchor while the universal bar is in restposition.

3. A variable key touch typewriter, as claimed in claim 1, havingindividual returning springs anchored to the respective key actions, andalso having an anchor member to which all of said key action returningsprings are anchored and which is adjustable to vary the stress of saidsprings collectively and thereby further regulate the operating touch ofthe key actions.

4. A variable key touch typewriter having, in combination, a universalbar, a set of individually operable key actions for imparting fingerpowered strokes to said bar, a key touch regulating spring for said setof actions, and means mounted independently of said bar and supportingsaid spring at its ends comprising an adjustable holding anchor for onespring end and an anchor for the other spring end which is movable backand forth relatively to said bar along the path of finger poweredstrokes of the bar and is variably positionable along said path by saidspring and the adjustable anchor to yieldingly oppose finger poweredstrokes of the bar.

5. A variable key touch typewriter, as claimed in claim 4, wherein saidholding anchor is supported for adjustment about a fixed axis and theother anchor is supported for rocking thereof about said axis intoabuttive engagement with the holding anchor by said spring and out ofsuch engagement by said bar, and wherein the spring is a helical springattached at its opposite ends to its respective anchors at pointsradially offset from said axis.

6. In a typewriter having a set of individually operable key actions,the combination with said set of actions of a tappet which is drivableby each of said actions through finger powered strokes of substantiallyequal range and which is biased to return to a rest position, an elementadvanceable toward said tappet about a fixed axis for retractive drivingof said element about said axis by said tappet on its finger poweredstrokes, and means adjustable about said axis to selectively set saidelement about said axis into and out of the range of finger poweredstrokes of said tappet and to exert a like advancing effort on saidelement in its respective, set positions.

7. A typewriter, as claimed in claim 6, wherein the means forselectively setting said element comprises a second element adjustableabout said axis to limit advance of the first element about said axistoward said tappet, and a spring connecting said elements to yieldinglyadvance the first element against the second element.

3. In a variable key touch typewriter, the combination of a set of keys,a tappet biased to a normal position from which it is drivable throughfinger powered strokes in a fixed path by said keys, an adjusting leverhaving a handle and rockable about a fixed axis, means for releasablylatching the adjusting lever in selectively adjusted positions, meansfor limiting the range of adjustment of the adjusting lever, a secondlever variably advanceable about said axis toward the tappet intoadvance-arresting engagement with the adjusting lever for retractivedriving of the second lever by the tappet on its finger powered strokes,a spring engaged with both of said levers to normally yieldinglymaintain the second lever in advance-arresting engagement with theadjusting lever in allv positions of the adjusting lever Within itslimited adjustment range.

9. A variable key touch typewriter, as claimed in claim 8, having aspring for biasing the tappet to its normal position, and meanssupporting the tappet for movements by its biasing spring and by thekeys about a fixed axis which is parallel to the axis about which theadjusting leverand second lever are movable.

CHARLES H. KENNEDY, JR.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,082,538 Lorenz Dec. 30, 1913 2,069,298 Avery Feb. 2, 1937

